EP1788748A1 - Method of operating a device in a radio access network of a radio communication system as well as radio access network and device - Google Patents

Abstract

The method involves arranging a transmission device between a base station (BTS) and a radio controller (BSC) of a radio access network. A control signal (S1) at a time period (t1) is received from the base station. An acknowledgement signal (B1) at a time period (t2) is sent as answer on the control signal to the base station, and a control signal (S2) is sent to the radio controller. The acknowledgement signal (B1) is partly sent even when an acknowledgement signal (B2) is not received between the two time periods. Independent claims are also included for the following: (1) a radio access network comprising a device for detection of connection interruptions in a radio access network of a radio communication system (2) a device for detection of connection interruptions in a radio access network of a radio communication system.

Description

The invention relates to a method for operating a device in a radio access network of a radio communication system and to a corresponding radio access network and a corresponding device.

In radio access networks, for example in accordance with the GSM (Global System for Mobile Communications) standard, control signals, so-called heartbeats, are transmitted between interconnected network elements, through which connection interruptions can be detected.

Connection interruptions occur, for example, when signals transmitted on a connection between two network elements are so strongly attenuated that the respective network element provided for reception can no longer detect the signals to be received. A connection between network elements takes place, for example, wired or via an air interface. For example, connections over an air interface experience unpredictable disconnections because the signal transmission path is subject to random fluctuations that are inherent in the nature of the air interface - examples include atmospheric noise or signal interference from adjacent frequency bands. Furthermore, connection interruptions can arise due to a failure of a network element.

If, for example, a radio station receives a corresponding control signal (heartbeat) from a radio control or a radio control, a confirmation signal is sent in response, by means of which the control signal receiving station recognizes that the control signal has been received and the connection thus exists at present. Detects a network element of a radio access network, such as a radio station or a radio control, a Connection interruption, ie no acknowledgment signal is received on a sent control signal, all existing data connections are aborted and must be rebuilt to their continuation.

Such control signals for checking a connection are exchanged between network elements of radio access networks with a predetermined repetition rate. Connection interruptions that begin and also end between two time points each intended for the detection of acknowledgment signals can not be detected. All connection interrupts that last longer than the time interval between two detection times, or that only occur after the reception of a first control signal but last until the reception time of a second control signal that depends on the predetermined repetition rate, are detected. A detection with a high predetermined repetition rate can lead to a disadvantage in that also connection interruptions are detected and thus lead to the termination of a current data transmission whose duration is so short that they are not critical for a data transmission carried out at this time. If it is detected with a low predetermined repetition rate, a connection interruption with a duration that is disturbing, for example in the case of time-critical data transmission, may not be detected.

The invention is therefore based on the object to provide an advantageous method and an advantageous radio access network and an advantageous device for detecting connection interruptions in a radio access network with a predetermined repetition rate for control signals for the detection of connection interruptions, by means of which the duration of detectable connection interruptions can be changed.

This object is achieved with the method, the radio access network and the device according to the independent claims.

Advantageous embodiments and further developments of the invention are the subject of dependent claims.

In the method according to the invention for operating a device in a radio access network of a radio communication system, the device is arranged between a first network element and a second network element of the radio access network, receives a first control signal from the first network element at a first time, and transmits a first acknowledgment signal at a second time Response to the first control signal to the first network element, wherein the first confirmation signal to the first network element signals that there is a connection between the first network element and the second network element. At a third time, the device sends a second control signal to the second network element, the second network element, upon receipt of the second control signal, sending a second acknowledgment signal to the device to signal the device the existence of a connection between the device and the second network element , According to the invention, the device sends the first confirmation signal at least partially even if no second confirmation signal was received between the first time and the second time.

In the radio communication system, it is provided, for example, that between network elements for checking the existence of a connection, the first control signal is transmitted and in response the first confirmation signal is transmitted when the connection is established. The invention now makes it possible that the first network element is signaled the existence of a connection even if the device - and thus the first network element - has no connection to the second network element or not informed about whether they connect to the second Network element, since it has not received a second acknowledgment signal. The device can thus be operated such that the first network element assumes a connection to the second network element although at the time of receiving the first acknowledgment signal, there may not be any connection to the second network element. The device thus makes it possible to ignore a connection interruption between the first and second network element.

Advantageously, the first and the second control signal are repeatedly received and transmitted and used in each case different repetition rates.

In this way, the radio communication system can be operated such that, by using a first repetition rate for the first control signal, connection interruptions having a first duration which is greater than or equal to the reciprocal of the first repetition rate can always be detected if no device according to the invention is used between network elements becomes. By using the device at a second repetition rate for the second control signal, it can be achieved that connection interruptions that would have been detected without the second control signal are not detected. This can be achieved, for example, by the second repetition rate being less than the first repetition rate. Interruptions of a respective duration greater than or equal to the inverse of the first repetition rate but less than the inverse of the second repetition rate are not detected in this case if they occur between two reception times of the second control signal given by the second repetition rate. It can thus be achieved by the invention that connection interruptions between the first and the second network element are not detected and thus ignored with a duration that would have been detected in the exclusive use of the first repetition rate waiving the use of the device in each case, and thus, for example would have resulted in a connection abort for a subscriber station connected, for example, to the first network element.

Advantageously, the repetition rate for the second control signal depends on the type of connection between the device and the second network element.

Under the type of connection, both the type of data transmitted, e.g. Real-time data or non-real-time data, as well as the physical nature of the connection, e.g. Satellite connection, electrical connection, connection by means of optical frequencies, understood.

The repetition rate of the second control signal can advantageously be selected so that a high repetition rate is selected for time-critical connections, with which even very small connection interruptions can be reliably detected. For non-time critical compounds, e.g. Data transfers for software download, or at system idle, e.g. no calls whose data must be forwarded between the first and second network element, a low repetition rate for the second control signal can be selected so that between two transmission times of the second control signal, the connection between the device and the second network element can even be deliberately interrupted. The latter is advantageous, for example, for cost-intensive satellite connections in order to save costs. It is thus advantageous if the repetition rate of the second control signal is adjusted so that its reciprocal is smaller than the shortest duration of a connection interruption, which is to be detected with certainty.

In one development of the invention, it is provided that data of a radio connection of a subscriber station of the radio communication system are transmitted between the first network element and the second network element. Furthermore, the device detects an interruption of its connection to the second network element and takes over for the duration of the interruption to the first network element exchange and / or processing of data that are needed to maintain the radio connection.

In this way it is achieved that even if a connection interruption is detected, for example because the device does not receive a second acknowledgment signal in response to the second control signal sent by it, a connection interruption to the subscriber station of the radio communication system is nevertheless avoided.

A further embodiment of the invention provides that the device receives data for establishing a data transmission to a subscriber station of the radio communication system which can be reached via the second network element via the first network element. After the device detects an interruption of its connection to the second network element, it stores the data received for establishing the data transmission and sets up the data transmission based on the stored data as soon as there is a connection to the second network element.

In this way it is avoided that the establishment of a data transmission, i. the establishment of a connection must be signaled again after it has been established in an attempt to establish the data transmission that there is a break in a connection between the first and the second network element.

Advantageously, the device sends the subscriber station and / or a station, which wishes to set up a data transmission, information regarding the interruption of the connection.

Such information is, for example, an announcement from a voice mail system, which informs that after completion of the interruption of the connection, the radio connection and thus the transmission of the data is continued or that the data transfer desired by the station, for example, automatically set. In this way, it can be achieved that a subscriber who is the subscriber station or operated the station, on its own the radio connection breaks or waived the establishment of the data transmission, because the connection was interrupted.

According to one embodiment of the invention, the first network element is arranged hierarchically above the second network element.

A development of the invention provides that the first network element is a radio control and the second network element is a radio station.

An alternative development provides that the first network element is a radio station and the second network element is a radio control.

A further embodiment of the invention provides that a further device between the device and the second network element is arranged and sends instead of the second network element on receipt of the second control signal in response to the second confirmation signal to the device.

By using two devices, between which the second control signal and the second confirmation signal are exchanged instead of the first control signal and the first confirmation signal, it is possible to use the invention in a radio access network such that both first network elements and second network elements already in one Radio access network operated without the invention, do not need to be changed in order to use the invention in the radio access network can. Advantageously, the further device is designed to send the third network element a third acknowledgment signal in response to a third control signal received by the second network element. The third confirmation signal signals to the second network element that there is a connection to the first network element. The further device is furthermore designed to transmit the third confirmation signal at least temporarily, even if there is no connection to the device and thus to the first network element, or if the further device has no corresponding information about the state of the connection - eg, by a second acknowledgment signal received by the device in response to a second control signal sent to the device.

Both the first network element and the second network element thus receive information from the device or the further device that there is a connection between the first and second network element, even if the device and / or the further device in each case do not receive a second acknowledgment signal that signals to them that there is a connection between the device and the other device. Even with an interruption of the connection between the device and further device is made possible by the invention, the first and second network element to signal yet that a connection between the first and second network element.

Advantageously, the further device or the second network element of a station with which the subscriber station exchanges data sends information regarding the interruption of the connection.

It is particularly advantageous if a transmission of control signals between the device and the second network element or between the device and the further device takes place via an air interface.

In particular in radio access networks, in which radio connections for data transmission are used between network elements, it may be advantageous if connection interruptions that would be detected when using the first control signal and the first confirmation signal are not detected by using the device and / or the further device become.

For example, a radio link between a radio station located in an aircraft and an associated radio control located on the ground is realized by a satellite system. This can lead to short connection interruptions, which are, however, not critical for carrying out the data transmission for a data transmission carried out at the moment of the connection interruption due to the short duration of the connection interruption. Therefore, in a conventional radio access network using only the first control signal and the first acknowledgment signal for detecting connection interruptions, unnecessary disconnections may occur without the invention when a connection interruption is detected by the first control signal and the first acknowledgment signal. This is advantageously avoided by using the device and / or the further device.

Further, for example, satellite links are expensive and may advantageously be intermittently intentionally interrupted, for example, if there is no payload (e.g., talk data) for transmission because the first and second network elements continue to receive first and third acknowledgment signals, respectively. In this way costs are saved during the connection interruption. For example, established over the first and second network element call connection between, for example, two subscriber stations but is not canceled automatically by the invention due to the intentional connection interruption.

In addition, the invention may also be implemented such that the second control signal or the second confirmation signal are sent at a higher repetition rate than the first control signal and the first confirmation signal. In this way, in the case of very real-time critical applications, for example real-time applications, it is also possible to detect connection interrupts which are shorter than connection interrupts which are used by means of the first control signal and the first acknowledgment signal would be detectable at a single rigidly fixed repetition rate.

The invention achieves a great variability for the detection of connection interruptions. Furthermore, it is achieved that subscribers who, for example, operate a subscriber station and are exposed to a connection interruption can be prevented from terminating a conversation or a data transmission by the aforementioned information about the connection interruption. Rather, they are encouraged by the information to wait until the disconnect is complete. For example, subscribers may also be signaled that no charges are being charged while waiting for the connection to end. For this purpose, the device and / or the further device advantageously sends a corresponding signal to a charging center of the radio communication system.

The radio access network according to the invention and the device according to the invention in each case have all the features that are required for carrying out the method according to the invention. In particular, corresponding means for carrying out the individual method steps or method variants can be provided in each case.

Fig. 1

eine erste schematische Darstellung eines erfindungsgemäßen Verfahrens zum Betrieb einer Vorrichtung,

Fig. 2

eine zweite schematische Darstellung eines erfindungsgemäßen Verfahrens zum Betrieb einer Vorrichtung und einer weiteren Vorrichtung, und

Fig. 3

eine dritte schematische Darstellung eines erfindungsgemäßen Verfahrens.

The invention will be explained in more detail below with reference to embodiments illustrated in the figures. Show it:

Fig. 1

a first schematic representation of a method according to the invention for operating a device,

Fig. 2

a second schematic representation of a method according to the invention for operating a device and a further device, and

Fig. 3

a third schematic representation of a method according to the invention.

Like reference numerals in the figures indicate like objects.

A subscriber station is, for example, a mobile radio terminal, in particular a mobile telephone or even a portable or stationary device for transmitting image and / or audio data, fax, Short Message Service SMS, multimedia messaging service MMS and / or email dispatch and / or to the internet access.

A network element of a radio access network of a radio communication system is, for example, a radio station or a radio control.

A radio station is, for example, a base station which receives user and / or signaling data from a subscriber station and / or transmits useful and / or signaling data to the subscriber station. A base station is connected via network facilities to a core network via which connections are made to other radio communication systems or to other data networks. Under a data network, for example, the Internet or a landline with, for example, circuit-switched or packet-switched connections for e.g. Understand language and / or data. A network-side device is, for example, a radio controller which serves to control radio transmissions between the base station and subscriber stations. A connection between the base station and a radio control can take place both via an air interface, for example a satellite connection, or via a line, for example via an electrical or optical connection.

The invention can be used advantageously in any radio communication systems. Radio communication systems are systems in which a data transmission between radio stations via an air interface. Data transmission can be bidirectional as well as unidirectional. Radio communication systems are in particular any mobile radio systems, for example according to the GSM (Global System for Mobile Communications) or the UMTS (Universal Mobile Telecommunications System) standard. Future mobile radio systems, for example the fourth generation, as well as ad hoc networks are to be understood by radio communication systems. Radio communication systems are also, for example, wireless local area networks (WLANs) according to the standards IEEE (Institute of Electrical and Electronics Engineers) 802.11ai, HiperLAN1 and HiperLAN2 (HiperLAN: high performance radio local area network) as well as Bluetooth networks and broadband networks wireless access, for example, according to IEEE 802.16.

In the following, the invention is described using the example of a radio communication system according to the GSM standard, but without wishing to express that the invention should be limited thereto.

Figure 1 shows schematically a base station BTS as a first network element, a device V with a processor P for controlling the device V and as a second network element a radio control BSC, by means of which radio links between subscriber stations and the base station BTS can be controlled. The base station BTS, the device V and the radio control BSC are arranged in a radio access network of a radio communication system.

Regardless of whether the base station BTS maintains a radio connection with a subscriber station, the radio access network of the radio communication system is operated such that a first control signal from the base station BTS is sent to the radio control BSC at a first repetition rate R1 for checking the connection. If the base station BTS receives a first acknowledgment signal B1 in response to the first control signal S1, it is signaled by the fact that the Connection between the base station BTS and the radio control BSC is not interrupted.

According to the invention, the device V is arranged between the base station BTS and the radio control BSC. The device V intercepts the first control signal S1 determined for the radio control BSC and signals the base station BTS by sending the first acknowledgment signal B1 that there is a connection to the radio control BSC. In order to obtain information on the existence of a connection with the radio control BSC itself, the device V sends a second control signal S2 with a second repetition rate R2 to the radio control BSC which, upon receipt of the second control signal S2 in response, sends a second acknowledgment signal B2 to the device V sends and the device V signaling that there is a connection to the radio control BSC.

The time interval between the reception of the first control signal and / or the second control signal until the transmission of the first acknowledgment signal and / or the second acknowledgment signal is for example fixed or variably adjustable for the device V and / or the radio control BSC. Preferably, the transmission of the first acknowledgment signal and of the second acknowledgment signal respectively takes place immediately after receipt of the first control signal or of the second control signal.

By using different repetition rates R1, R2 for the first control signal S1 and the second control signal S2, the first control signal S1 may for example be transmitted by the base station BTS at a time t1 'and subsequently received by the device V at a first time t1 which lies between two transmissions of the second control signal S2 through the device V. At the first time t1 of the reception of the first control signal S1, the second confirmation signal B2 received on the last transmission of the second control signal S2 is already obsolete (The last reception of the second acknowledgment signal is for example more than 1 / (2 * R2) back.) And another second acknowledgment signal B2 is not yet available. The device therefore can not make a reliable assumption about whether there is a connection to the radio control BSC. Nevertheless, the device V sends the first acknowledgment signal B1 to the base station BTS at the second time t2. The base station BTS is thus signaled that there is a connection between the base station BTS and the radio control BSC. In fact, during a period marked A in FIG. 1, the connection between the device V and the radio control BSC was interrupted. However, this period was between the two transmissions of the second control signal S2 shown and was therefore not detected.

In the exclusive use of the first control signal without the device V, the first control signal would have been sent from the base station BTS to the radio controller BSC during the disconnection and the base station BTS would not have received the first acknowledgment signal B1 at the second time. It would thus come to a connection break for existing data transfers. By means of the invention, however, the base station BTS receives the first acknowledgment signal B1 and an unillustrated existing data transmission can be continued despite the connection interruption, since a second time T3 at which the second control signal S2 is sent from the device V to the radio control BSC , the interruption does not exist anymore.

The second repetition rate R2 in this exemplary embodiment is selected, for example, such that connection interruptions whose duration does not exceed the time interval between two transmissions of the second control signal S2, ie 1 / R2, and which thus depend on their relative timing with respect to the transmitted second Control signals S2 may not be detected, are not disturbing to existing data transfers.

According to FIG. 1, the second control signals S2 and the second acknowledgment signals B2 are transmitted between the device V and the radio control BSC via an air interface. For example, the radio station BTS is arranged in an aircraft, wherein the device V is also arranged in the aircraft and is either arranged in the radio station BTS or directly connected to it. The radio control BSC is arranged, for example, on the ground and a radio connection between the device V and the radio control BSC takes place via a satellite connection. In this embodiment, the second repetition rate R2 due to the satellite connection is less than the first repetition rate R1. In this way, a likelihood of disconnection due to a connection interruption between device V and radio control BSC is less than would be the case if also the second control signal S2 were transmitted at the first repetition rate.

In this embodiment, the radio controller BSC is compared with other radio controls in the radio access network of the radio communication system, which are not connected to a device corresponding device V, adapted to process the second control signal S2 and send the second confirmation signal B2 in response. The radio access network has, for example, further radio controls and further radio stations which, for example, are both arranged on the ground and between which, for example, the first control signal S1 and the first confirmation signal B1 are directly conducted, i.e. line-connected. be sent without a corresponding device.

In addition to the transmission direction of the first control signal S1 and of the second control signal S2 illustrated in FIG. 1, it can likewise be provided that the device V itself transmits the first control signal S1 to the radio station BTS in order to receive the first acknowledgment signal B1 from the radio station BTS. Furthermore, it can be provided be that the radio control BSC in turn sends the second control signal S2 to the device V in response to receive the second confirmation signal B2. In this way, in a manner analogous to that described for FIG. 1, the respectively reverse transmission direction can be checked for connection interruptions. This is particularly advantageous if the transmission directions have different transmission properties, for example due to different frequencies and / or due to different transmission paths.

For reasons of clarity, transmissions in the aforementioned transmission directions have not been shown in FIG.

FIG. 2 schematically shows a sequence corresponding to the time sequence of the transmission of first control signals S1 and second control signals S2 and first confirmation signals B1 and second confirmation signals B2 according to FIG.

Also in this embodiment occurs in a period designated by B between a first transmission of the second control signal S2 from the device V and a second transmission of the second control signal S2 from the device V on a connection interruption. In this case, too, the radio station BTS is nevertheless signaled by the device V that a connection to the radio control BSC has been established, in which the device V responds twice during the period B to a received first control signal S1 with a first acknowledgment signal B1.

In contrast to the embodiment of Figure 1, in this embodiment, between the device V and the radio control BSC another device V 'is arranged, which is controlled by a further processor P'. The further device V 'receives instead of the radio control BSC second control signals S2 from the device V and transmits on receipt in response to confirmation of an existing connection between the device V and the further device V ', the second confirmation signal B2.

In order to check whether there is a connection between the radio station BTS and the radio control BSC, the radio control BSC transmits, for example, a third control signal S3 to the radio station BTS at the same repetition rate with which the radio station BTS transmits the first control signal S1. The third control signal S3 is intercepted by the further device and in response the radio control BSC receives a third acknowledgment signal B3, which signals the radio control BSC that there is a connection to the radio control BSC. In this way, for example, during the period B, the radio control BSC is signaled that there is a connection to the radio station BTS. In the same way, the further device V 'checks the connection to the radio control BSC with the third control signal and, when received in response, receives the third acknowledgment signal. The transmission direction is not shown for reasons of clarity.

The third control signal is also transmitted, for example, at the first repetition rate R1 and, for example, synchronously with the first control signal S1. Of course, the third control signal S3 can also be sent at a different repetition rate and / or asynchronously.

As described with reference to FIG. 1, alternatively or additionally a transmission of the first and second control signals S1, S2 as well as of the first and second confirmation signals B1, B2 can take place in the respectively reverse direction. However, these transmission directions are not shown in FIG. 2 for reasons of clarity.

The use of the further device V 'makes it possible to use the invention also in radio communication systems in which radio stations and radio controls are used, they themselves are not able to support the method according to the invention. For example, the third control signal S3 corresponds to the first control signal S1 and is provided in the radio access network to be transmitted between network devices, for example between the radio station BTS and the radio controller BSC, without a device V and a further device V 'disconnecting the connection using the first Repeat rate R1 between the radio station BTS and the radio control BSC to be able to detect.

The exemplary embodiment according to FIG. 2 is preferably used in a radio access network in which the radio station BTS is arranged in an aircraft, while the radio control BSC is located on the ground. The device V is also arranged in the aircraft. The further device V 'is connected to the device V via a radio link, such as a satellite link and is located as well as the radio control BSC on the ground.

In Figure 2, the second control signal S2 between the device V and the other device V ', for example, with a further repetition rate R2' is sent, which is greater than the second repetition rate R2 according to the embodiment of Figure 1. In this way, even longer periods of time for Connection interruptions tolerated as this is the case according to Figure 1 with the second repetition rate R2. For example, in the interruption of the connection shown in Figure 2 during the period B, an intentional interruption of the connection between the device V and the further device V ', for example, connection time on a costly satellite connection between the device V and the other device To save V '. During the period B, for example, the satellite connection is not needed because of the absence of data to be transmitted. Nevertheless, both the radio station BTS and the radio control BSC continue to signal the existence of a connection, so that existing Radio links from subscriber stations that are connected to the radio station BTS, but for example, during the period of time B have no data to transmit, are not interrupted, although the satellite connection between the device V and the other device V 'for the period B was interrupted.

This possibility does not exist in radio communication systems with radio access networks in which the first control signal is transmitted directly between the radio station BTS and the radio control BSC exclusively at the first repetition rate. Namely, in this case, an intentional or unintentional interruption of the connection between the radio station BTS and the radio control BSC would have been detected during the period B and would have involved an abort of all data transmissions, i. all radio links between subscriber stations and the radio station BTS pulled.

A development of the invention is shown schematically in FIG. Also in the embodiment of FIG. 3, first control signals S1 are transmitted from the radio station BTS to the device V, and second control signals S2 are sent from the device V to the radio control BSC, as already described with reference to FIG. For reasons of clarity, however, only second control signals S2 of the device V are shown. At the beginning of the time stream in FIG. 3, a subscriber station MS maintains a connection with a station ST, the subscriber station being connected to the radio station BTS via a radio link, and the station ST being connected to the radio control BSC via further devices, not shown, in order to obtain data D to exchange with the subscriber station MS via the device V and the radio station BTS.

The device V transmits the second control signal S2 to the radio control BSC and does not receive the second acknowledgment signal B2 within a reception period provided for this purpose. This is shown in FIG. 3 by streaking by means of a Cross of the connecting arrow, which represents the second confirmation signal B2, expressed. The device V thus recognizes that the connection to the radio control BSC is interrupted. At the same time, the device receives from a further subscriber station MS 'via the radio station BTS signaling data AUFB, by means of which the further subscriber station MS' set up a data transmission, ie would like to establish a connection to the station ST. The device V stores this connection establishment request, ie the signaling data AUFB, in order to use the signaling data AUFB for automatically setting up the data transmission when there is again a connection to the radio control BSC.

Furthermore, the device V exchanges first signaling data SIG1 with the radio station BTS, which contain all information required, for example, according to a radio standard used to maintain the radio connection between the subscriber station MS and the radio station BTS. For the radio station BTS and the subscriber station MS, therefore, a connection to the station ST still seems to exist. Furthermore, the radio controller BSC also recognizes, for example because it does not receive a second acknowledgment signal B2 for a second control signal S2 sent to the device, or because it has not received a second control signal from the device V at a given time, that the connection to the device V is interrupted. The radio controller BSC therefore takes over the exchange of second signaling data SIG2 with the station ST in order to signal the station ST that there is still a connection with the subscriber station MS.

Furthermore, the device V of the subscriber station MS sends a first information I1, and the radio control BSC sends the station ST a second information I2. The first and second information I1, I2 can each be deduced that the connection is temporarily interrupted, but a data transmission can be continued as soon as there is a connection. The device V sends a third piece of information 13 to the further subscriber station MS ', which can be deduced that the connection is temporarily interrupted, but the desired data transmission is set up automatically as soon as a connection is established. The first information I1, the second information I2 and the third information I3 are, for example, in each case an announcement from a speech memory system which serves a respective subscriber who operates the subscriber station MS, the further subscriber station MS 'or the station ST Communication interruption as a voice message informs and prompts not to abort the connection manually, since the data transmission continues after restoring the connection or the desired data transmission is set up automatically. The first, second and third information I1, I2 thus serve to inform a respective subscriber of the stations concerned, who can manually terminate the connection or abort the establishment of a data transmission, and do not intervene in the operation of the stations. On the other hand, the first and second signaling data SIG1, SIG2 of the subscriber station MS and the station ST are signaled unnoticed by the respective subscribers and control the operation of the stations MS, ST such that the respective connection is not automatically aborted due to the interrupted connection.

Subsequently, the device V again sends the second control signal S2 to the radio controller BSC and, since the connection interruption no longer exists, receives the second confirmation signal B2 for the confirmation of the existing connection. Thereupon, the device V initiates a connection setup with the station ST on the basis of the stored signaling data AUFB via the radio control BSC representative of the further subscriber station MS 'and thus establishes the data transmission. In this way, it is avoided that the further subscriber station MS 'has to retransmit the signaling data AUFB required to establish a connection, ie to set up a data connection, because of the detected connection interruption.

Furthermore, after the device V has determined the completion of the interruption, the data transmission between the subscriber station MS and the station ST has continued.

As an alternative to the illustration in FIG. 3, the exemplary embodiment according to FIG. 3 can also be carried out by arranging the further device V 'between the device V and the radio control BSC, as already described for FIG. 2, and assuming those functionalities which were previously described with reference to FIG 3 were taken over by the radio control BSC. In this case, the invention can in turn be used without the radio stations or radio controls used in an existing radio access network itself having to be changed.

The exemplary embodiment of FIG. 3 also finds its preferred application in the case where the further subscriber station MS ', the subscriber station MS, the radio station BTS and the device V are arranged in an aircraft, a satellite connection exists between the device V and the radio control BSC and the radio control BSC is located on the ground. The station ST can be arranged in the radio communication system in which the subscriber stations MS, MS 'are located as well as arranged in another radio communication system. For example, the station ST can also be a telephone in a fixed network or a computer connected to a radio communication system, for example by means of a radio module.

Of course, the signaling shown in Figures 1 to 3 can also be done in the reverse direction by the first control signal S1 from the radio control BSC to the device V and the further device V 'is sent and the device V, the second control signal S2 in the case 1 and 3 sends to the radio station BTS or receives the third control signal S3 in the case of Figure 2 from the radio station BTS. This corresponds to the previously described embodiments with in the figures interchanged position of the radio station BTS and the radio control.

The inventive device V is integrated, for example, in the radio control BSC or connected to this via an electrical or an optical line. The inventive further device V 'is integrated, for example, in the radio control BSC or connected to this via an electrical or an optical line.

The device V and the further device V 'are realized, for example, wholly or partly as a computer program product. In the context of the present invention, computer program product, apart from the actual computer program (with its technical effect beyond the normal physical interaction between the program and the arithmetic unit), contains in particular a record carrier for the computer program, a file library, a configured arithmetic unit, e.g. a computer, but also for example a storage device or a server on which the computer program associated files are stored, understood.

With regard to the computer program product, the computer program can have program sections for carrying out the method according to the invention described above.

A connection established for setting up a data transmission is also called a logical connection. By the invention, the termination of a logical connection can be avoided, even if a physical connection between two network elements is interrupted or disturbed, are transmitted over the data in the context of the logical connection.

Claims (15)

Method for operating a device (V) in a radio access network of a radio communication system, in which the device (V) is arranged between a first network element (BTS) and a second network element (BSC) of the radio access network, receives a first control signal (S1) from the first network element (BTS) at a first time (t1), - At a second time (t2) sends a first confirmation signal (B1) in response to the first control signal (S1) to the first network element (BTS), wherein the first confirmation signal (B1) the first network element (BTS) signals that a connection between the first network element (BTS) and the second network element (BSC), a second control signal (S2) is sent to the second network element (BSC) at a third point in time (t3), the second network element (BSC) receiving a second confirmation signal (B2) in response to the device (S2) receiving the second control signal (S2) V) for signaling to the device (V) the existence of a connection between the device (V) and the second network element (BSC), - And at least partially transmits the first confirmation signal (B1) even if between the first time (t1) and the second time (t2) no second confirmation signal (B2) was received. The method of claim 1, wherein
the first and second control signals (S1, S2) are repeatedly received and transmitted and each have different repetition rates (R1, R2). Method according to one of the preceding claims, in which
the repetition rate (R2) of the second control signal (S2) depends on the type of connection. Method according to one of the preceding claims, in which between the first network element (BTS) and the second network element (BSC), data (D) of a radio connection of a subscriber station (MS) of the radio communication system are transmitted, the device (V) detects an interruption of its connection to the second network element (BSC), - And for the duration of the interruption to the first network element (BTS) an exchange and / or processing of data (SIG1) takes over, which are needed to maintain the radio connection. Method according to one of the preceding claims, in which - the device (V) via the first network element (BTS) receives data (AUFB) for establishing a data transmission to a via the second network element (BSC) reachable subscriber station (ST) of the radio communication system, the device (V) detects an interruption of its connection to the second network element (BSC), - And the device (V) stores the data received for setting up the data transmission (AUFB) and establishes the data transmission on the basis of the stored data (AUFB) as soon as a connection to the second network element (BSC) exists. A method according to claim 4 or 5, wherein
the device (V) of the subscriber station (MS) and / or a station (MS ') wishing to set up a data transmission sends information (I1, I3) regarding the interruption of the connection. Method according to one of the preceding claims, in which
the first network element (BTS) is arranged hierarchically over the second network element (BSC). Method according to one of the preceding claims, in which the first network element is a radio control (BSC) and the second network element is a radio station (BTS). Method according to one of claims 1 to 6, in which
the first network element is a radio station (BTS) and the second network element is a radio control (BSC). Method according to one of the preceding claims, in which
a further device (V ') is arranged between the device (V) and the second network element (BSC) and in response to the second network element (BSC) receiving the second control signal (S2) in response to the second confirmation signal (B2) to the device (BSC) V) sends. The method of claim 10, wherein
the further device (V '), in response to a third control signal (S3) received from the second network element (BSC), signals the second network element (BSC) with the third acknowledgment signal (B3) to pass to the first network element (BTS) without that the further device (V ') has corresponding information. Method according to one of claims 4 to 11, in which
the further device (V ') or the second network element (BSC) of a station (ST), with which the subscriber station (MS) exchanges data, sends information (I2) regarding the interruption of the connection. Method according to one of the preceding claims, in which
a transmission of signals (S2, B2) between the device (V) and the second network element (BSC) or between the device (V) and the further device (V ') takes place via an air interface. Radio access network having at least one device (V) with means (P) for carrying out a method according to one of Claims 1 to 13. Device (V) with means (P) for carrying out a method according to one of claims 1 to 13.

Images